Title:
【発明の名称】ピリド[1,2―a]ピリミジン誘導体の新規製造法
Document Type and Number:
Japanese Patent JP2997494
Kind Code:
B2
Abstract:
PURPOSE:To obtain the title compound by making, from 3-cyano-4-imino- pyrido[1,2-a]pyrimidine derivative as starting material, a new intermediate either through another new intermediate or by direct tetrazole-cyclization of the nitrile group of said derivative and by hydrolysis of the resulting new intermediate. CONSTITUTION:A compound of formula I [R<1> and R<3> are each H or alkyl; R<2> and R<4> are each H, halogen, alkyl, phenyl or of formula II (R<5> is H or OH; R<6> is H or acyl; R<7> is H, alkyl or allyl)] is reacted with hydrazoic acid or its salt to effect tetrazole-cyclization of the nitrile group of said compound into a new compound of formula III followed by acting an acid or base on this compound to prepare a second new compound of formula IV, which is then hydrolyzed to obtain the objective compound, a pyrido[1,2-a]pyrimidine derivative of formula V. Alternatively, the compound of the formula I is, without through the new compound of the formula III, directly converted into the new compound of the formula IV, which is then hydrolyzed to obtain the objective compound of the formula V. The above process is excellent in terms of yield, safety, operability, etc.
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Inventors:
Atsunori Sano
Masami Ishihara
Jun Yoshihara
Hiromi Nawa
Masami Ishihara
Jun Yoshihara
Hiromi Nawa
Application Number:
JP4081790A
Publication Date:
January 11, 2000
Filing Date:
February 21, 1990
Export Citation:
Assignee:
Wako Pure Chemical Industries, Ltd.
T.T.Pharma Co., Ltd.
T.T.Pharma Co., Ltd.
International Classes:
A61K31/505; A61P37/08; C07D401/12; C07D471/04; A61K31/519; (IPC1-7): C07D471/04; C07D401/12